Hydrocarbon-substituted thiacyclopentane-1,1-dioxide



Patented Apr. 1948 5 PAT ENT OFFICE HYDROCABBON-SUBSTITUTED CLOPENTANE-Ll-DIOXIDE Rupert 0. Morris, Berkeley, Calif., assignor to Shell Development Company, San Francisco, Calif., a corporation of Delaware No Drawing. Application July 13, 1943 Serial No. 494,587

' 4 Claims. 1

This invention relates to a novel and particularly useful class of compounds. More particularly, the invention pertains to a certain novel and useful class of substituted cyclic sulfones. Specifically, the invention is directed to sulfolanes and sulfolenes having at least one substituted or unsubstitutedunsaturated hydrocarbon radical attached to a nuclear carbon atom of the sulfolane or sulfolene ring by means of a single carbon-to-carbon linkage.

The term sulfolene, as employed herein and in the appended claims, refers to an unsaturated structure containing four carbon atoms, a single olefin linkage between any two adjoining carbon atoms, and a sulfur atom in a ring, the sulfur is atom of this five-membered heterocyclic unsaturated ring having two oxygen atoms attached thereto. This compound has also been called thiacyclopentene-1,1-dioxide."

This compound has also been termed thiacyclopentane 1,1 dioxide," "thiolane-1,1-dioxide, cyclotetramethylene sulfone, or dihydro butadiene sulfone. Generically, the term "sulfolane" covers not only the above compound, but also the substituted derivatives of this compound. As stated, the double bond in the sulfolenes may be between'any two of the adjacent carbon atoms of the ring, the generic, term "sulfolene" covering both the simple, unsubstituted sulfolenes, i. e.,

s-sulfolene having the structure:

nc-=-on H: H: I

n 4 and z-sulfolene having the structure:

m :--cn HCL Ila,

as well as the various derivatives thereof. 1. e. sulfolenes iu-which various radicals are substituted for one or more of the hydrogen atoms of the above structures. It is an object of thepresent invention to provide a newclass of chemical compounds. A further object is to provide a novel class of compounds possessing unexpectedly useful properties. Other objects will be apparent from the following description of the present invention.

Unsubstituted sulfolane, as well as both unsubstituted sulfolenes, i. e. z-sulfolene and 3-sulfolene, have been known for some time. Also, some substituted, solfolanes and sulfolenes have been previously prepared. In sum! these compounds the side chain or chains attached via a carbon-to-carbon bond to the ring consisted of saturated aliphatic or aromatic radicals. Substituted sulfolanes and sulfolenes containing a methylene group-directly attached to a nuclear carbon atom by a double bond are also known. It has now been discovered that sulfolane and sulfolene derivatives containing a substituted or unsubstituted unsaturated hydrocarbon radical attached to the ring by a single carbon-to-carbon linkage, surprisingly possess inherent properties which render said compounds unexpectedly and markedly superior to those of the corre- Broadly, the novel compounds of the present invention consist of substituted sulfolanes and sulfolenes containing at least one substituted and/or unsubstituted, unsaturated hydrocarbon radical attached to the sulfolane or sulfolane ring via a single carbon-to-carbon linkage. In the case of the sulfolane derivatives, the novel compounds may be represented by the following general structural formula:

lat-4n;

wherein at least one of the R. radicals attached to the .nuclearcarbon atoms is an unsubstituted Y a or substituted, unsaturated hydrocarbon radithe exception that the sulfolene ring contains at least one double bond between two adjacent carbon atomsof the ring structure. For instance, with a double bond in the betaor I i-position. the'novel sub-class of compounds of the present invention is represented by the following general structural formula:

wherein at least one of the R radicals is an unsubstituted or substituted. unsaturated hydrocarbon radical attached to a nuclear carbon atom by a single carbon-to-carbon linkage, while the remaining R radicals are the same or different substituents of the character described above with reference to the corresponding novel sub-class of substituted sulfolane derivatives.

A preferred sub-group of novel compounds comprises the-sulfolanes and sulfolenes in which va'single unsubstituted or substituted, unsaturated hydrocarbon radical is attached via a single carbon-to-carbon linkage to the ring at the 2- or '3-position, the remaining free bonds of the nuclear carbon atoms being taken up by hydrogen atoms, halogen atoms, hydroxyl radicals and/or saturated aliphatic radicals.

The numbering system of the sulfolane (thiolane) or sulfolene ring is indicated below:

C--cl' This is in accordance with the accepted system of numbering as exemplified by the compounds of this type of ring structure givenon page 44 of Patterson and Capell, The Ring Index, Reinhold Publishing Corp., New York, 1940; Am. Chem. Soc. Monograph No. 84. The system may be exemplified by the compound having the structure:

CH1=CHCH:-CHCH1 which is named 3-allylsulfolane, and the compound CHI-=03 armors-tn m which is called 2-vinyl-3-sulfolene. Another subgroup of novel compounds comprises the sulfolanes and sulfoleneshaving two or more of the aforementioned unsaturated substituents attaehedto the ring. each by means a asinh carbon-to-carbon linkage. This group may be exemplified by 2,5-divinyl-3-sulfolene which has the following structural formula:

on=cn om=on-on 11-01::0111 2K 0 o The unsaturated, unsubstituted or substituted radicals attached to the sulfolane or suliolene ring include: the unsaturated hydrocarbon radicals having a single bond for attachment to the ring, e. g. vinyl, allyl, propenyl, crotyl, methyl vinyl carbinyl, butenyl, pentenyl, hexenyl, methallyl, isocrotyl, cyclopentenyl, cyclohexenyi, isopentenyl; octenyl, nonenyl, oleyl, cinnamyl and phenyl vinyl carbinyl radicals, as well as the unsaturated radicals of the type of the halo-substituted derivatives of the above and other similar unsaturated hydrocarbon radicals, such as 2-chlor-allyl, 3-chlor-allyl, 2-br0m-ally1, 2-bromcrotyl, 2-chlor-crotyl, and the like; the oxygenated derivatives of the above class of unsaturated hydrocarbon radicals, i. e. their aldehydes, alcohols,'glycols, ethers, esters, ketones, and similar oxygenated derivatives, all of which derivatives have a single bondfor the attachment of the radical to the sulfolane or. sulfolene ring via a carbon-to-carbon connection, the following being examples of such radicals:

and the like, and their homologues and analogues; unsaturated organic compounds containing a sulfur atom (such as the unsaturated thio-ether radicals) and/or a nitrogen atom or atoms, e. g. radicals or groups of the type of -cH=cn-s-cm cu=cn'-scu='cuz -cn=cnnm -Cli=CilNH-Clii and the like, and their homologues and analogues;

as well as combinations thereof, e. g. unsaturated amide or sulfonate radicals. In all of these cases,

' the unsaturated organic radical is attached directly to a carbon atom ofthe sulfone ring via a single carbon-to-carbon linkage. As mentioned above, the novel class of sulfolanes and sulfolenes contains at least one such unsaturated organic radical, the remaining free bonds of the carbons of the sulfolane or sulfolene ring being satisfied with the same or different atoms or groups, such as hydrogen atoms, halogen atoms, hydroxyl radicals, or organic radicals, which are preferably hydrocarbon radicals, and especially saturated acyclic radicals.

Excluded from the scope of the invention are 7 those compounds wherein the substituent or substituents attached to the sulfone ring containno other carbon-to-carbon double bonds except those of an aryi, e. g. a phenyl, group. This is because a phenyl group is not considered by those skilled in the art to be an unsaturated radical. Thus, a phenyl group does not possess the necessary unsaturation within the meaning of the term "unsaturated as used herein, and it is the presence of the unsaturated group or groups (which are in the side chain proper, and not between the ring and said chain) which gives the compounds of the invention their characteristic superior properties as compared to the corresponding or similar substituted sulfolanes or substituted sulfolenes devoid of'such unsaturation. It will be understood, however, that the compounds which possess unsaturated groups in addition to the aryl group are not to be construed as excluded from the scope of the invention, reference being i beta-(z-A -sulfolenyl) divinyl ether, 2'- 2-h droxyallyl) A3 sulfolene, 2 4 hydroxy 2 butenyl) A sulfolene, beta -(3-A=- sulfolenyl) acrolein; alpha-(4-vinyl-2-suifolanyl) acetaldehyde, vinyl -8-sulfolanyl ketone, isopropenyl 3-sulfolanyi ketone, ailyl' 2,4-dimethyl-3-M-sul foienyl ketdne, allyl beta-(3-sulfolanyl) -ethyl 'poly-olefinic' hydrocarbon containing at least three oleflnic linkages, at least two of which are in conjugated position, with sulfur dioxide under conditions favoringan addition reaction. The following is a specific example of the application of this procedure to the production of 2-vinyl-3- sulfolene. Substantially peroxide-free hexatriene (i. e. a hydrocarbon having the general structural formula CH2=CHCH=CHCH==CH2) is mixed with liquid sulfur dioxide, which is preferabiy' employed in an amount which is at least stoichiometricaily sufllcient to react, moi per mol, with said hexatriene. These reactants are then heated to an elevated temperature which is however below that .at which the cyclic monosulfones thus formed will decompose. Generally, this reaction temperature is in the neighborhood ofabout C. However, somewhat higher temperatures may also be used as long as they are below the aforementioned decomposition temperature. The reaction is conducted for a period of time sufllcient to effect the desired degree of interaction between the sulfur dioxide and the poly-olefin, this residence time depending on the specific poly-olefin treated, the employed mol ratio of sulfur dioxide to the polyolefln, the operating pressure, and other operating conditions. Thus, the above hexatriene reacts readily with sulfur dioxide when the reaction is efiected at the above-mentioned temperature and at a pressure which maintains the reactants in the liquid state, or at least maintains a liquid phase in the reaction zone (e. g. a pressure of between about 100 lbs. per sq. in. and about 500 lbs. per sq. in), particularly when the sulfur dioxide is employed in an amount which is greatly in excess of that necessary tocombine with the hexatriene. 0n the other hand, acyclic poly-olefins containing a tertiary unsaturated carbon atom.

which carbon atom is one of the two to which the sulfur dioxide adds to form the cyclic unsaturated sulfone, require a comparatively considerably longer residence time to attain the same degree of conversion. As stated, under the optimum conditions of operation mentioned above (1. e. a reaction temperatureof about 100 0., a superatmospheric pressure sumcient to maintain the reactants in the liquid state, and the use of for example about 4 mols of liquid sulfur dioxide per mol of the hexatriene), a substantially quantitative conversion to 2-vinyl-3-sulfolene will be attained by effecting the above reaction between hexatriene and sulfur dioxide for a period of only a few minutes, e.-g. a residence time of less than one hour, the reaction product containing only V sulfolene to the action of hydrogen at substantially atmospheric pressures and temperatures, and in the presence of a suitable hydrogenation catalyst, e. g. pyrophoric nickel metal catalyst,

platinum, or the like, to form z-ethyl-sulfolane,

this latter being then catalyticaily dehydrogenated to produce the desired 2-vinyl-sulfolane. Care should be taken to conduct the last-men- .tioned dehydrogenation reaction under such con-.

I ditions and for such a period of time that dehydrogenation occurs only in the side-chain (and even this only to the desired degree) and that there is no or substantially no dehydrogenation of the sulfolane ring proper.

Another method of producing sulfolanes con- Y taining an unsaturated hydrocarbon radical attached to the ring via a single carbon-to-carbon linkage comprises a reaction between a poly-olefinic ester, e. g. a poly-oleflnic acetate, and sulfur dioxide to form the corresponding substituted sulfolene, this latter being then hydrogenated and the reaction product thus produced being then treated, e. g. by heating to a suitable temperature to split of! acetic acid. For instance, hexadieneacetate may be reacted with sulfur dioxide under the above-outlined conditions which iavor the formation of the following substituted sulfolene derivative:

This compound may then be subjected to hydrogenation, for example, by reacting it with hydro- T gen under substantially atmospheric pressure and in the presence 01' a hydrogenation catalyst, such as pyrophoric nickel, to saturate the double bond in the sulfone ring. When thissaturated compound is then heated, for instance to a temperature of from about 200 C. to about 500 0., acetic acid is split ofl, thus producing 2-vinylple, 2,4-dimethyl-3-chloro-A -su1folene may be reacted with methallylmagnesium chloride to V form 2,4 dimethyl 3 methallyl-M-sulfolene.

8 Similarly, 2.3-dimethyi-2-bromo-sulfoiane may be reacted with crotylmagnesium bromide to produce 2,3-dimethyl-2-crotyl-sulfolane.

The products of the present invention are of value in a large variety of industries and as intermediates in various chemical syntheses. For

instance, at least some of these compounds are highly useful as plasticizers and tackiflers in natural and synthetic compositions, while some of the same and other compounds of the novel class are ofvalue in the resin and lacquer industry as solvents and plasticizers for the manufacture of dopes, fabriccoatings, sprays and moulding .compositions. Other uses are as insecticides, an-

tioxidants, pourpoint depressants, extracting agents, ingredients in cosmetics, as base materials and fixing agents in the preparation of perfumes, as softening agents for the leather industry, and as selective solvents in extractive dis tillation processes.

I claim as my'invention:

1. Z-vinyl-sulfolane having the general structural formula 2. A hydrocarbon-substituted thiacyclopentane-1,1-dioxide containing as the sole substituent an alkenyl radical attached to a nuclear carbon atom of the thiacyclopentane-1,1-dioxide ring via a single carbon-tocarbon linkage.

3. A hydrocarbon-substituted thiacyclopentane-1,l-dioxide containing as the sole substituent an alkenyl radical of not more than four carbon atoms attached directly to a nuclear carbon atom of the thiacyclopentane-1,1-dioxide ring via a single carbon-to-carbon linkage.

4. A hydrocarbon-substituted thiacyclopentane-1,1-dioxide having "an unsubstituted unsaturated hydrocarbon radical, which radical is directly attached to a nuclear carbon atom of the thiaoyclopentane-l,l-dioxide ring via a single carbon-to-carbon linkage, said unsaturated hydrocarbon radical containing at least one unsaturated linkage between two carbon atoms of aliphatic character.

RUPERT C. MORRIS.

REFERENCES CITED The following references are of record in the Pays-Bas, vol. 58 (1939), pages 778-784. 

